package data_structure.date12_22;

import java.util.ArrayList;
import java.util.Collection;

public class Demo3 {
    public static void main(String[] args) {
        Collection collection = new ArrayList();
        System.out.println(collection.size());//0
        System.out.println(collection.isEmpty());//true
        System.out.println(collection.contains(1));//false

        System.out.println(collection.add(1));//true
        System.out.println(collection.size());//1
        System.out.println(collection.isEmpty());//false
        System.out.println(collection.contains(1));//true
    }
}